The 2 oscillator circuits under are appropriate for making use of crystal oscillators in sequence or parallel mode: Substantial-repetition-price and superior-electric power picosecond regenerative amplifier depending on a single bulk Nd:GdVO4 crystal A timing reference incorporating an individual-crystal-silicon micromechanical resonator with a quality issue of larger than one million in https://www.hxcrystals.com/seokeywords/bulk-crystal-oscillator.html